In this guide, I will walk you through different methods to identify and control fruitworms on tomato plants.
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- What Is Fruitworm And How It Harms Tomato Plants?
- How To Confirm That Fruitworm Is Troubling Your Tomato Plants?
- Natural Ways To Control Fruitworm On Tomato Plants
- Physical Ways To Control Fruitworm On Tomato Plants
- Chemical Ways To Control Fruitworm On Tomato Plants
- How To Prevent Fruitworm In Tomato Plants?
- What Causes Fruitworm Attacks In Tomato Plants?
- Frequently Asked Questions
What Is Fruitworm And How It Harms Tomato Plants?
Tomato fruitworm, also known as corn earworms are medium-sized moths that feed on both the leaves and the tomato fruit.
They have characteristic dark and light stripes or black spots that run along their body. They grow to about two inches long and are nocturnal.
How To Confirm That Fruitworm Is Troubling Your Tomato Plants?
Fruitworm preferably attacks green fruit. The most distinct feature of fruitworm damage is small black holes in the ripening fruit usually at the stem end.
When you cut these tomatoes open, you may find tunneling through the entire tomato. Also, they leave the interior of tomatoes filled with water, frass, decay, and droppings.
You may also see fruitworms clinging to the fruits.
Natural Ways To Control Fruitworm On Tomato Plants
The different natural and organic methods to control fruitworms on tomato plants are the application of diatomaceous earth powder, Bt, neem oil, and the release of beneficial parasites.
Method 1- Diatomaceous Earth
Diatomaceous Earth (DE) powder consists of the fossilized exoskeleton of algae. It will dehydrate the fruitworms by piercing their skin and killing them.
- Purchase DE powder– DE powder is available in stores and can be easily purchased
- Sprinkle DE powder– Sprinkle the powder as a thin layer around the tomato plants. You may also dust the powder on the plants.
Take care to avoid inhaling this powder as it may damage the lungs.
Avoid dusting on tomato plants when flowering as it may kill beneficial honeybees.
Here is a useful video on using DE powder:
Method 2- Bacillus thuringiensis
Bacillus thuringiensis (Bt) will paralyze the digestive system of fruitworms larvae and kill them. It is a microbial biological control available in liquid, powder, and granule forms.
- Apply Bt– Dilute ½ teaspoon of organic Bt in one liter of water. Spray Bt at the first sign of worm eggs on the foliage of affected plants. It is preferable to apply in the afternoon or evening as Bt may break down in UV light.
- Reapply– Reapply the Bt spray after a week to prevent infection.
Check out this useful video on how to use Bt:
Method 3- Neem Oil
Neem oil helps in interfering with the normal lifecycle of fruitworms, including feeding, molting, mating, and egg laying.
- Apply neem oil– Spray neem oil on the susceptible foliage. Avoid spraying in the middle of the day as the high heat may burn the foliage sprayed with neem oil.
- Reapply– You may reapply after a week. Take care to use neem oil only once a week for best results.
Method 3- Release Beneficial Parasites
The naturally occurring beneficial parasites, including Trichogramma pretiosum may help in the biological control of tomato fruitworms.
- Collect beneficial predators– Trichogramma parasites can be purchased from many commercial insectaries.
- Release parasites– Release these beneficial parasites when the tomato fruit is susceptible to fruitworm feeding. Alternatively, you may practice conservation biocontrol to let wild wasps in your tomato garden
Physical Ways To Control Fruitworm On Tomato Plants
Inspect the tomato plants and handpick the fruitworms if you spot them. Also, remove the damaged fruits to prevent further infestation.
Handpicking the larvae is the best non-toxic way of controlling fruitworms.
- Monitor the tomato plants– Inspect the tomato plants carefully for any larvae.
- Handpick the larvae– Remove the larvae using the hands and destroy them. You may plunge them in a soapy solution to kill them.
- Remove the damaged tomatoes– It is preferable to remove the damaged and rotting tomatoes as they may harbor fruitworms. It will prevent the spread of infection.
Chemical Ways To Control Fruitworm On Tomato Plants
The weekly sprays of chemical insecticides for fruitworms should begin as soon as the tomatoes bloom and set fruit. It is difficult for insecticides to act when the larvae enter the fruit.
Spinosad is an organically approved insecticide that can be effective against tomato fruitworm. When consumed, it will lead to paralysis and the death of fruitworms.
- Prepare the spinosad– Wear gloves and cover the arms to reduce exposure. Dilute the spinosad concentrate according to the manufacturer’s instructions.
- Spray the spinosad– Apply the spinosad to the top and bottoms of the leaves and stems when you see larvae. Avoid applying when the tomato plants are in bloom or shedding pollen.
Acetamiprid is a chemical pesticide used for treating tomato fruitworm. It has less impact on naturally occurring parasites and other insect predators.
- Prepare the diluted solution– Follow the instructions of the manufacturer and prepare the diluted solution.
- Spray the solution– Spray the foliage when you spot or suspect fruitworm infestation.
How To Prevent Fruitworm In Tomato Plants?
Tomato fruitworm infestations may be prevented by tilling the soil before planting, covering the plants, and practicing crop rotation. You may also avoid planting other local food sources.
Method 1- Change The Garden Environment
Remove the infected plants and destroy them at the end of the season to avoid possible infection. You may also till the soil deeply to destroy the pupae.
You can plant insectary strips in your tomato garden. It includes white alyssum, dill, asters, daisies, stinging nettle, and yarrow.
This will help in attracting parasitic wasps that will help in keeping fruitworms in check.
Method 2- Reduce Local Food Sources
Avoid planting the other hosts of fruitworms, including corn, cotton, tobacco, or peppers near the tomatoes. This helps in reducing the other sources of food for these worms.
Method 3- Practice Crop Rotation
I prefer to practice crop rotation in my tomato garden so that they are not grown in the same place every year. The crop rotation will reduce the possibility of infection from fruitworm eggs hiding in the soil.
Method 4- Cover Tomato Plants
You may cover the tomato plants using row cover or fine netting. It will help in preventing the fruitworm from entering the fruits.
What Causes Fruitworm Attacks In Tomato Plants?
Fruitworms may survive the winter and remain in the soil. If the soil is not tilled properly before planting tomatoes, the fruitworm may sporadically attack these plants.
Also, their attacks may be worse in soil with weed infestations.
Frequently Asked Questions
No, the fruitworm-infested tomato fruits can not be eaten and have to be discarded. They leave behind nasty droppings, liquid, and other remnants inside the fruit. The tomato decays and rots quickly making them inedible.
Tomato fruitworms can be differentiated from hornworms with the size and presence of the horn. Fruitworms are smaller than hornworms with no horns and are found in burrowing tunnels inside the fruit. Hornworms are much larger with the distinctive horn on the front.
Yes, diluted soapy water can be used to deter fruitworms. Dissolve a small amount of liquid soap in warm water in a spray bottle. Spray the affected foliage to discourage fruitworms from eating tomato fruits.
I hope this guide has highlighted different methods to identify and tackle the fruitworm attacks on tomato plants.
I am interested to hear if you have tried any other method that has worked for you.
Check out details on other issues associated with tomato plants here>